diff --git a/README.md b/README.md
index b1fdaf7..ffbf040 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,10 @@ module Jsonifier
 
   alias_visit_method :serialize
 
+  def_serialize String do |object|
+    '"' + object.to_s + '"'
+  end
+
   # […]
 end
 
diff --git a/lib/eavi/visitor.rb b/lib/eavi/visitor.rb
index 416c5e8..f9ba254 100644
--- a/lib/eavi/visitor.rb
+++ b/lib/eavi/visitor.rb
@@ -103,6 +103,8 @@ module MethodsWhenIncluded
 
       def specialized_alias_visit_method(visit_method_alias)
         define_method(visit_method_alias, instance_method(:visit))
+        define_singleton_method(('def_' + visit_method_alias.to_s).to_sym, method(:def_visit))
+        define_singleton_method(('undef_' + visit_method_alias.to_s).to_sym, method(:undef_visit))
       end
 
       def specialized_add_visit_method(type, block)
@@ -130,6 +132,8 @@ module MethodsWhenExtended
 
       def specialized_alias_visit_method(visit_method_alias)
         define_singleton_method(visit_method_alias, method(:visit))
+        define_singleton_method(('def_' + visit_method_alias.to_s).to_sym, method(:def_visit))
+        define_singleton_method(('undef_' + visit_method_alias.to_s).to_sym, method(:undef_visit))
       end
 
       def specialized_add_visit_method(type, block)
diff --git a/test/visitor_test.rb b/test/visitor_test.rb
index de6ae5e..4951d89 100644
--- a/test/visitor_test.rb
+++ b/test/visitor_test.rb
@@ -135,13 +135,11 @@
       it do
         Reader.class_eval do
           alias_visit_method :read
-
-          def_visit Page do
-            # [...]
-          end
         end
 
         assert_respond_to @reader, :read
+        assert_respond_to Reader, :def_read
+        assert_respond_to Reader, :undef_read
       end
     end
 
@@ -350,13 +348,11 @@
       it do
         Printer.class_eval do
           alias_visit_method :print
-
-          def_visit Page do
-            # [...]
-          end
         end
 
         assert_respond_to Printer, :print
+        assert_respond_to Printer, :def_print
+        assert_respond_to Printer, :undef_print
       end
     end